Prognostic Significance of Silent Myocardial Ischemia in Acute Myocardial Infarction

Silent myocardial ischemia is proved to be a marker of unfavorable outcomes in coronary artery disease patients. However it has a predictive value in patients early after acute myocardial infarction and its relationship with left ventricular systolic and diastolic dysfunction remains uncertain. The aim of the study is to evaluate the functional changes and specific course of myocardial infarction with symptomatic and silent myocardial ischemia.
119 patients with first Q wave myocardial infarction were included into the study. All of them underwent routine coronary angiography, 24-hour electrocardiographic monitoring, Doppler ECHO of transmitral and transaortal flows with assessment of diastolic and systolic left ventricular function on the 2nd day of disease.
Prospective follow-up was made during 1 year. Factorial and discriminate analysis were undertaken to estimate the most predictable criteria for complicated course of myocardial infarction.
Groups of patients with signs of mixed (symptomatic and silent) and only silent ischemia episodes have more severe coronary artery lesions, pronounced left ventricular systolic and diastolic dysfunction in comparison with group of patients without signs of ischemia. Complicated course of myocardial infarction developed in 52.7%, 45.7% and 12% of patients, respectively (p<0.05).
The most predictable criteria for unfavorable prognosis in early post myocardial infarction patients were presence of silent myocardial ischemia, its overall duration more than 60 minutes/per 24 hour, mean number of injured coronary arteries, E value, Ei/ai, aortal flow mean acceleration and EF.